Virology Commons^™

Breaking Into Hiv-1'S Epigenetic Vault: Cure Strategies To Eliminate The Viral Reservoir, Joanna Jones, Chelsea Gunderson, Brian Wigdahl, Michael Nonnemacher

Kimmel Cancer Center Faculty Papers

Human immunodeficiency virus type 1 (HIV-1) is a retrovirus that integrates into the host cell's DNA as a provirus. Transcription from the provirus is regulated in large part by cellular proteins and epigenetic factors. These may be repressive or permissive to productive infection. The host factors that regulate this balance are therefore attractive targets for HIV-1 therapeutics. Indeed, proviral chromatin is the focus of two of the current HIV-1 cure strategies. "Shock and Kill" uses latency reversal agents to open the provirus's chromatin, promoting high levels of gene expression that induce the killing of infected cells. "Block and Lock" uses …

Exploring The Transformative Effects Of Calorie Restriction On The Lacrimal Gland In Adult Mice, Olivier Mauduit, Prashant Kumar, Kaitlin K Scholand, Emre Aksan, Laura Schaefer, Anmar Abu-Romman, Vanessa Delcroix, Zhiyuan Yu, Aude I Sindikubwabo, Ron Korstanje, Helen P Makarenkova, Cintia S De Paiva

Faculty, Staff and Students Publications

Advanced age is one of the most recognizable risk factors for dry eye. Dry eye disease affects millions worldwide and can result from age-related lacrimal gland dysfunction, which correlates with a decline in lacrimal gland secretory cell function and chronic inflammation. This study investigated the potential of calorie restriction to maintain lacrimal gland and ocular surface health. Adult female C57BL/6 J mice were subjected to a 40% calorie restriction for 4 months, starting at 6-7 months and continuing until 10-11 months. These mice were compared to controls fed ad libitum. Bulk RNA sequencing of lacrimal glands, conjunctiva, and cornea subjected …

Elephant Endotheliotropic Herpesvirus 2 Infection In 5 African Elephants (Loxodonta Africana) At Multiple North American Zoological Institutions, Taylor J Willis, Anne Burgdorf-Moisuk, Maren Connolly, Jan Raines, Cameron Ratliff, Zoltan S Gyimesi, Erica Lipanovich, Genevive A Dumonceaux, Kathryn L Perrin, Lauren L Howard, Matthew E Kinney, Kirk Suedmeyer, Erin Latimer, Tiffany L Kim, Jessica R Watts, Jie Tan, Paul Ling

Faculty, Staff and Students Publications

Objective: To acknowledge that elephant endotheliotropic herpesvirus (EEHV) is a well-recognized major threat to Asian elephants (Elephas maximus) and can cause acute and often fatal hemorrhagic disease (HD). Historically, EEHV-HD has been less frequently identified in African elephants (Loxodonta africana). This case series describes 5 recent cases of EEHV2 infection in African elephants within managed care at 5 North American institutions.

Animals: 5 African elephants (L africana).

Clinical presentation: The cases involved 4-, 7-, and 10-year-old males that died despite receiving aggressive medical therapy and 4- and 14-year-old females that survived. Clinical signs included lethargy, decreased appetite, lameness, changes in …

Dietary Lipids Induce Ppard And Bcl6 To Repress Macrophage Il-23 Induction After Intestinal Injury And Lps Exposure, Ashleigh M Gil, Daniel F Zegarra-Ruiz, Wan-Jung Wu, Kendra Norwood, Adrien Assie, Buck S Samuel, Angela M Major, Gretchen E Diehl, Andrea A Hill Mcalester

Faculty, Staff and Students Publications

Unresolved tissue damage is a common feature of Inflammatory Bowel Disease (IBD) that facilitates disease progression. Here, we showed that high animal fat diets (HFD), an environmental risk factor associated with IBD pathogenesis, suppress intestinal macrophage production of critical tissue repair responses after damage. This includes reduced IL-23 production, which drives downstream production of IL-22, which is needed for barrier repair. Indicating that dietary lipids interfere with responses to microbial molecules needed to induce barrier protective functions, we found oleic acid could directly suppress macrophage Il23a induction after lipopolysaccharide (LPS) treatment. Deleting the lipid transporter CD36 on macrophages restored the …

Oral Dosing Of The Nucleoside Analog Obeldesivir Is Efficacious Against Rsv Infection In African Green Monkeys, Jared Pitts, J Lizbeth Reyes Zamora, Savrina Manhas, Thomas Aeschbacher, Josolyn Chan, Vincent Cutillas, Varsha Nair, Nicholas C Riola, Arya Vijjapurapu, Meghan S Vermillion, Stacey Eng, Christopher Richards, Dong Han, Jason K Perry, Subhra Chaudhuri, Szu-Wen Liu, Clarissa Martinez, Nadine Peinovich, Kai-Hui Sun, Arthur Cai, Ross Martin, Jasmine Moshiri, Charlotte Hedskog, Darius Babusis, Dustin S Siegel, Rao Kalla, Vasanthi Avadhanula, Pedro A Piedra, Kim Stobbelaar, Peter L Delputte, Caleb Marceau, Roberto Mateo, Evguenia Maiorova, Hongmei Mo, Raju Subramanian, Richard L Mackman, Tomas Cihlar, Simon P Fletcher, John P Bilello

Faculty, Staff and Students Publications

Respiratory syncytial virus (RSV) is a significant cause of morbidity and mortality in high-risk populations. Although prophylactic options are available, there are no effective oral therapeutics for RSV infection. Obeldesivir (ODV) is an orally bioavailable prodrug of the nucleoside analog GS-441524, which is converted intracellularly to its active nucleoside triphosphate and inhibits the RSV RNA polymerase. Here we report the potent antiviral activity of ODV against geographically and temporally diverse RSV A and B clinical isolates (EC50: 0.20–0.66 μM). Resistance selection studies with ODV and GS-441524 against RSV identify a single amino acid substitution, I777L, in the L polymerase with …

Microbial Biosensor For Sensing And Treatment Of Intestinal Inflammation, Duolong Zhu, Jeffrey Galley, Jason Pizzini, Elena Musteata, Martin V Douglas, Walter J Chazin, Eric P Skaar, Jeffrey J Tabor, Robert A Britton

Faculty, Staff and Students Publications

Synthetic biology has enabled the development of biosensors to detect intestinal inflammation, yet few target the clinically validated biomarker of intestinal inflammation calprotectin with both diagnostic and therapeutic capabilities. Here, an optimized calprotectin biosensor is presented that leverages a zinc uptake regulator (Zur) controlled promoter coupled with a memory circuit to detect and record intestinal inflammation in vivo. The level of biosensor activation strongly correlates with calprotectin levels in the colon of two independent mouse models of colitis. Coupling of the biosensor with the production of the anti-inflammatory cytokine IL10 allowed for the resolution of chemically induced colitis, demonstrating the …

Phage-Induced Protection Against Lethal Bacterial Reinfection, Yikun Xing, Haroldo J Hernandez Santos, Ling Qiu, Samantha R Ritter, Jacob J Zulk, Rachel Lahowetz, Kathryn A Patras, Austen L Terwilliger, Anthony W Maresso

Faculty, Staff and Students Publications

Bacteriophages, or phages, are viruses that target and infect bacteria. Due to a worldwide rise in antimicrobial resistance (AMR), phages have been proposed as a promising alternative to antibiotics for the treatment of resistant bacterial infections. Up to this point in history, phage use in preclinical animal studies, clinical trials, and emergency-use compassionate care cases has centered around the original observation from 1915 showing phage as lytic agent, and thus a treatment that kills bacteria. Here, we describe an activity associated with phage therapy that extends beyond lytic activity that results in long-term protection against reinfection. This activity is potent, …

Aged Regulatory T Cells Fail To Control Autoimmune Lacrimal Gland Pathogenic Cd4+ T Cells, Kaitlin K Scholand, Laura Schaefer, Gowthaman Govindarajan, Zhiyuan Yu, Jeremias G Galletti, Cintia S De Paiva

Faculty, Staff and Students Publications

CD25KO mice are a model of Sjögren disease. CD25KO mice have severe inflammation and infiltrating lymphocytes to the lacrimal glands (LG). Whether the pathogenicity of CD25KO CD4+ T cells can be controlled in vivo by Tregs is unknown. Eight-week-old B6 and CD25KO mice LGs were submitted for RNA bulk sequencing. A total of 3481 genes were differentially expressed in CD25KO LG compared to B6. Tear washing analysis identified CD25KO mice had elevated protein levels of TNF, IFN-γ, and CCL5 and decreased protein levels of IL-12p40 and VEGF-A. Co-adoptive transfer of CD25KO CD4+ T cells with either young or aged B6 …

Control Of Clostridioides Difficile Virulence And Physiology By The Flagellin Homeostasis Checkpoint Flic-Fliw-Csra In The Absence Of Motility, Duolong Zhu, Katherine J Wozniak, Firas Midani, Shaohui Wang, Xingmin Sun, Robert A Britton

Faculty, Staff and Students Publications

Mutations affecting Clostridioides difficile flagellin (FliC) have been shown to be hypervirulent in animal models and display increased toxin production and alterations in central metabolism. The regulation of flagellin levels in bacteria is governed by a tripartite regulatory network involving fliC, fliW, and csrA, which creates a feedback system to regulate flagella production. Through genomic analysis of C. difficile clade 5 strains (non-motile), we identified they have jettisoned many of the genes required for flagellum biosynthesis yet retain the major flagellin gene fliC and regulatory gene fliW. We therefore investigated the roles of fliC, fliW …

Viroporin Activity Is Necessary For Intercellular Calcium Signals That Contribute To Viral Pathogenesis, J Thomas Gebert, Francesca J Scribano, Kristen A Engevik, Ethan M Huleatt, Michael R Eledge, Lauren E Dorn, Asha A Philip, Takahiro Kawagishi, Harry B Greenberg, John T Patton, Joseph M Hyser

Faculty, Staff and Students Publications

Viruses engage in a variety of processes to subvert host defenses and create an environment amenable to replication. Here, using rotavirus as a prototype, we show that calcium conductance out of the endoplasmic reticulum by the virus encoded ion channel, NSP4, induces intercellular calcium waves that extend beyond the infected cell and contribute to pathogenesis. Viruses that lack the ability to induce this signaling show diminished viral shedding and attenuated disease in a mouse model of rotavirus diarrhea. This implicates nonstructural protein 4 (NSP4) as a virulence factor and provides mechanistic insight into its mode of action. Critically, this …

Tamm-Horsfall Protein Augments Neutrophil Netosis During Urinary Tract Infection, Vicki Mercado-Evans, Holly Branthoover, Claude Chew, Camille Serchejian, Alexander B Saltzman, Marlyd E Mejia, Jacob J Zulk, Ingrid Cornax, Victor Nizet, Kathryn A Patras

Faculty, Staff and Students Publications

Urinary neutrophils are a hallmark of urinary tract infection (UTI), yet the mechanisms governing their activation, function, and efficacy in controlling infection remain incompletely understood. Tamm-Horsfall glycoprotein (THP), the most abundant protein in urine, uses terminal sialic acids to bind an inhibitory receptor and dampen neutrophil inflammatory responses. We hypothesized that neutrophil modulation is an integral part of THP-mediated host protection. In a UTI model, THP-deficient mice showed elevated urinary tract bacterial burdens, increased neutrophil recruitment, and more severe tissue histopathological changes compared with WT mice. Furthermore, THP-deficient mice displayed impaired urinary NETosis during UTI. To investigate the effect of …

The Rise, Fall, And Resurgence Of Phage Therapy For Urinary Tract Infection, Jacob J Zulk, Kathryn A Patras, Anthony W Maresso

Faculty, Staff and Students Publications

In the face of rising antimicrobial resistance, bacteriophage therapy, also known as phage therapy, is seeing a resurgence as a potential treatment for bacterial infections including urinary tract infection (UTI). Primarily caused by uropathogenic Escherichia coli, the 400 million UTI cases annually are major global healthcare burdens and a primary cause of antibiotic prescriptions in the outpatient setting. Phage therapy has several potential advantages over antibiotics including the ability to disrupt bacterial biofilms and synergize with antimicrobial treatments with minimal side effects or impacts on the microbiota. Phage therapy for UTI treatment has shown generally favorable results in recent …

Sequencing-Based Detection Of Avian Influenza A(H5n1) Virus In Wastewater In Ten Cities, Michael J Tisza, Blake M Hanson, Justin R Clark, Li Wang, Katelyn Payne, Matthew C Ross, Kristina D Mena, Anna Gitter, Sara J Javornik Cregeen, Juwan Cormier, Vasanthi Avadhanula, Austen Terwilliger, John Balliew, Fuqing Wu, Janelle Rios, Jennifer Deegan, Pedro A Piedra, Joseph F Petrosino, Eric Boerwinkle, Anthony W Maresso

Faculty, Staff and Students Publications

No abstract provided.

Enterococcus Faecalis-Derived Adenine Enhances Enterohaemorrhagic Escherichia Coli Type 3 Secretion System-Dependent Virulence, Fernando H Martins, Thibaut Rosay, Anubama Rajan, Hannah E Carter, Tayah Turocy, Andres Mejia, Jason M Crawford, Anthony W Maresso, Vanessa Sperandio

Faculty, Staff and Students Publications

Interactions between microbiota and enteric pathogens can promote colonization resistance or enhance pathogenesis. The pathobiont Enterococcus faecalis increases enterohaemorrhagic E. coli (EHEC) virulence by upregulating Type 3 Secretion System (T3SS) expression, effector translocation, and attaching and effacing (AE) lesion formation on enterocytes, but the mechanisms underlying this remain unknown. Using co-infection of organoids, metabolomics, supplementation experiments and bacterial genetics, here we show that co-culture of EHEC with E. faecalis increases the xanthine-hypoxanthine pathway activity and adenine biosynthesis. Adenine or E. faecalis promoted T3SS gene expression, while transcriptomics showed upregulation of adeP expression, which encodes an adenine importer. Mechanistically, adenine relieved …

Identification And Characterization Of A Skin Microbiome On Caenorhabditis Elegans Suggests Environmental Microbes Confer Cuticle Protection, Nadia B Haghani, Robert H Lampe, Buck S Samuel, Sreekanth H Chalasani, Molly A Matty

Faculty, Staff and Students Publications

In the wild, C. elegans are emersed in environments teeming with a veritable menagerie of microorganisms. The C. elegans cuticular surface serves as a barrier and first point of contact with their microbial environments. In this study, we identify microbes from C. elegans natural habitats that associate with its cuticle, constituting a simple “skin microbiome.” We rear our animals on a modified CeMbio, mCeMbio, a consortium of ecologically relevant microbes. We first combine standard microbiological methods with an adapted micro skin-swabbing tool to describe the skin-resident bacteria on the C. elegans surface. Furthermore, we conduct 16S rRNA gene sequencing studies …

Progress Toward A Vaccine For Extraintestinal Pathogenic Coli (Expec) Ii: Efficacy Of A Toxin-Autotransporter Dual Antigen Approach, Yikun Xing, Justin R Clark, James D Chang, Jacob J Zulk, Dylan M Chirman, Felipe-Andres Piedra, Ellen E Vaughan, Haroldo J Hernandez Santos, Kathryn A Patras, Anthony W Maresso

Faculty, Staff and Students Publications

Extraintestinal pathogenic Escherichia coli (ExPEC) is a leading cause of worldwide morbidity and mortality, the top cause of antimicrobial-resistant (AMR) infections, and the most frequent cause of life-threatening sepsis and urinary tract infections (UTI) in adults. The development of an effective and universal vaccine is complicated by this pathogen’s pan-genome, its ability to mix and match virulence factors and AMR genes via horizontal gene transfer, an inability to decipher commensal from pathogens, and its intimate association and co-evolution with mammals. Using a pan virulome analysis of >20,000 sequenced E. coli strains, we identified the secreted cytolysin α-hemolysin (HlyA) as a …

Caenorhabditis Elegans Endorse Bacterial Nanocellulose Fibers As Functional Dietary Fiber Reducing Lipid Markers, Amanda Muñoz-Juan, Adrien Assié, Anna Esteve-Codina, Marta Gut, Núria Benseny-Cases, Buck S Samuel, Esther Dalfó, Anna Laromaine

Faculty, Staff and Students Publications

Bacterial nanocellulose (BNC) is a promising dietary fiber with potential as a functional food additive. We evaluated BNC fibers (BNCf) in the Caenorhabditis elegans model to obtain insight into the BNCf's biointeraction with its gastrointestinal tract while reducing the variables of higher complex animals. BNCf were uptaken and excreted by worms without crossing the intestinal barrier, confirming its biosafety regarding survival rate, reproduction, and aging for concentrations up to 34 μg/ml BNCf. However, a slight decrease in the worms' length was detected. A possible nutrient shortage or stress produced by BNCf was discarded by measuring stress and chemotactic response pathways. …

Sialic Acid-Siglec-E Interactions Regulate The Response Of Neonatal Macrophages To Group B Streptococcus, Sean J Lund, Pamela G B Del Rosario, Asami Honda, Kaitlin J Caoili, Marten A Hoeksema, Victor Nizet, Kathryn A Patras, Lawrence S Prince

Faculty, Staff and Students Publications

The mammalian Siglec receptor sialoadhesin (Siglec1, CD169) confers innate immunity against the encapsulated pathogen group B Streptococcus (GBS). Newborn lung macrophages have lower expression levels of sialoadhesin at birth compared with the postnatal period, increasing their susceptibility to GBS infection. In this study, we investigate the mechanisms regulating sialoadhesin expression in the newborn mouse lung. In both neonatal and adult mice, GBS lung infection reduced Siglec1 expression, potentially delaying acquisition of immunity in neonates. Suppression of Siglec1 expression required interactions between sialic acid on the GBS capsule and the inhibitory host receptor Siglec-E. The Siglec1 gene contains multiple STAT binding …

Metabolic Model Predictions Enable Targeted Microbiome Manipulation Through Precision Prebiotics, Georgios Marinos, Inga K Hamerich, Reena Debray, Nancy Obeng, Carola Petersen, Jan Taubenheim, Johannes Zimmermann, Dana Blackburn, Buck S Samuel, Katja Dierking, Andre Franke, Matthias Laudes, Silvio Waschina, Hinrich Schulenburg, Christoph Kaleta

Faculty, Staff and Students Publications

While numerous health-beneficial interactions between host and microbiota have been identified, there is still a lack of targeted approaches for modulating these interactions. Thus, we here identify precision prebiotics that specifically modulate the abundance of a microbiome member species of interest. In the first step, we show that defining precision prebiotics by compounds that are only taken up by the target species but no other species in a community is usually not possible due to overlapping metabolic niches. Subsequently, we use metabolic modeling to identify precision prebiotics for a two-member Caenorhabditis elegans microbiome community comprising the immune-protective target species Pseudomonas …

The Human Vaginal Microbiota: From Clinical Medicine To Models To Mechanisms, Samantha Ottinger, Clare M Robertson, Holly Branthoover, Kathryn A Patras

Faculty, Staff and Students Publications

The composition of the vaginal microbiota is linked to numerous reproductive health problems, including increased susceptibility to infection, pregnancy complications, and impaired vaginal tissue repair; however, the mechanisms contributing to these adverse outcomes are not yet fully defined. In this review, we highlight recent clinical advancements associating vaginal microbiome composition and function with health outcomes. Subsequently, we provide a summary of emerging models employed to identify microbe-microbe interactions contributing to vaginal health, including metagenomic sequencing, multi-omics approaches, and advances in vaginal microbiota cultivation. Last, we review new in vitro, ex vivo, and in vivo models, such as organoids and humanized …

Select Gut Microbiota Impede Rotavirus Vaccine Efficacy, Vu L Ngo, Yanling Wang, Yadong Wang, Zhenda Shi, Robert Britton, Jun Zou, Sasirekha Ramani, Baoming Jiang, Andrew T Gewirtz

Faculty, Staff and Students Publications

BACKGROUND & AIMS: The protection provided by rotavirus (RV) vaccines is highly heterogeneous among individuals. We hypothesized that microbiota composition might influence RV vaccine efficacy.

METHODS: First, we examined the potential of segmented filamentous bacteria (SFB) colonization to influence RV vaccine efficacy in mice. Next, we probed the influence of human microbiomes on RV vaccination via administering mice fecal microbial transplants (FMTs) from children with robust or minimal RV vaccine responsiveness. Post-FMT, mice were subjected to RV vaccination followed by RV challenge.

RESULTS: SFB colonization induced a phenotype that was reminiscent of RV vaccine failure (ie, failure to generate RV …

Age-Associated Temporal Decline In Butyrate-Producing Bacteria Plays A Key Pathogenic Role In The Onset And Progression Of Neuropathology And Memory Deficits In 3×Tg-Ad Mice, Paula M Chilton, Smita S Ghare, Benjamin T Charpentier, Scott A Myers, Aakarsha V Rao, Joseph F Petrosino, Kristi L Hoffman, John C Greenwell, Neetu Tyagi, Jyotirmaya Behera, Yali Wang, Lucy J Sloan, Jingwen Zhang, Christopher B Shields, Gregory E Cooper, Leila Gobejishvili, Scott R Whittemore, Craig J Mcclain, Shirish S Barve

Faculty, Staff and Students Publications

Alterations in the gut-microbiome-brain axis are increasingly being recognized to be involved in Alzheimer's disease (AD) pathogenesis. However, the functional consequences of enteric dysbiosis linking gut microbiota and brain pathology in AD progression remain largely undetermined. The present work investigated the causal role of age-associated temporal decline in butyrate-producing bacteria and butyrate in the etiopathogenesis of AD. Longitudinal metagenomics, neuropathological, and memory analyses were performed in the 3×Tg-AD mouse model. Metataxonomic analyses showed a significant temporal decline in the alpha diversity marked by a decrease in butyrate-producing bacterial communities and a concurrent reduction in cecal butyrate production. Inferred metagenomics analysis …

Vaccines Against Extraintestinal Pathogenic Escherichia Coli (Expec): Progress And Challenges, Ling Qiu, Dylan Chirman, Justin R Clark, Yikun Xing, Haroldo Hernandez Santos, Ellen E Vaughan, Anthony W Maresso

Faculty, Staff and Students Publications

The emergence of antimicrobial resistance (AMR) is a principal global health crisis projected to cause 10 million deaths annually worldwide by 2050. While the Gram-negative bacteria Escherichia coli is commonly found as a commensal microbe in the human gut, some strains are dangerously pathogenic, contributing to the highest AMR-associated mortality. Strains of E. coli that can translocate from the gastrointestinal tract to distal sites, called extraintestinal E. coli (ExPEC), are particularly problematic and predominantly afflict women, the elderly, and immunocompromised populations. Despite nearly 40 years of clinical trials, there is still no vaccine against ExPEC. One reason for this is …

Microbial Stimulation Of Oxytocin Release From The Intestinal Epithelium Via Secretin Signaling, Heather A Danhof, Jihwan Lee, Aanchal Thapa, Robert A Britton, Sara C Di Rienzi

Faculty, Staff and Students Publications

Intestinal microbes impact the health of the intestine and organs distal to the gut. Limosilactobacillus reuteri is a human intestinal microbe that promotes normal gut transit, the anti-inflammatory immune system, wound healing, normal social behavior in mice, and prevents bone reabsorption. Oxytocin impacts these functions and oxytocin signaling is required for L. reuteri-mediated wound healing and social behavior; however, the events in the gut leading to oxytocin stimulation and beneficial effects are unknown. Here we report evolutionarily conserved oxytocin production in the intestinal epithelium through analysis of single-cell RNA-Seq datasets and imaging of human and mouse intestinal tissues. Moreover, …

Vaginal Microbial Dynamics And Pathogen Colonization In A Humanized Microbiota Mouse Model, Marlyd E Mejia, Vicki Mercado-Evans, Jacob J Zulk, Samantha Ottinger, Korinna Ruiz, Mallory B Ballard, Stephanie W Fowler, Robert A Britton, Kathryn A Patras

Faculty, Staff and Students Publications

Vaginal microbial composition is associated with differential risk of urogenital infection. Although Lactobacillus spp. are thought to confer protection against infection, the lack of in vivo models resembling the human vaginal microbiota remains a prominent barrier to mechanistic discovery. Using 16S rRNA amplicon sequencing of C57BL/6J female mice, we found that vaginal microbial composition varies within and between colonies across three vivaria. Noting vaginal microbial plasticity in conventional mice, we assessed the vaginal microbiome of humanized microbiota mice (

Human Intestinal Organoids As Models To Study Enteric Bacteria And Viruses, Grace Adeniyi-Ipadeola, Hephzibah Nwanosike, Sasirekha Ramani

Faculty, Staff and Students Publications

Laboratory studies of host-microbe interactions have historically been carried out using transformed cell lines and animal models. Although much has been learned from these models, recent advances in the development of multicellular, physiologically active, human intestinal organoid (HIO) cultures are allowing unprecedented discoveries of host-microbe interactions. Here, we review recent literature using HIOs as models to investigate the pathogenesis of clinically important enteric bacteria and viruses and study commensal intestinal microbes. We also discuss limitations of current HIO culture systems and how technical advances and innovative engineering approaches are providing new directions to improve the model. The studies discussed here …

Gpr43 Stimulation On Tcrαβ+ Intraepithelial Colonic Lymphocytes Inhibits The Recruitment Of Encephalitogenic T-Cells Into The Central Nervous System And Attenuates The Development Of Autoimmunity, Carolina Prado, Alexandra Espinoza, J Eduardo Martínez-Hernández, Joseph Petrosino, Erick Riquelme, Alberto J M Martin, Rodrigo Pacheco

Faculty, Staff and Students Publications

INTRODUCTION: Gut microbiota plays a critical role in the regulation of immune homeostasis. Accordingly, several autoimmune disorders have been associated with dysbiosis in the gut microbiota. Notably, the dysbiosis associated with central nervous system (CNS) autoimmunity involves a substantial reduction of bacteria belonging to Clostridia clusters IV and XIVa, which constitute major producers of short-chain fatty acids (SCFAs). Here we addressed the role of the surface receptor-mediated effects of SCFAs on mucosal T-cells in the development of CNS autoimmunity.

METHODS: To induce CNS autoimmunity, we used the mouse model of experimental autoimmune encephalomyelitis (EAE) induced by immunization with the myelin …

Exercise Reprograms The Inflammatory Landscape Of Multiple Stem Cell Compartments During Mammalian Aging, Ling Liu, Soochi Kim, Matthew T Buckley, Jaime M Reyes, Jengmin Kang, Lei Tian, Mingqiang Wang, Alexander Lieu, Michelle Mao, Cristina Rodriguez-Mateo, Heather D Ishak, Mira Jeong, Joseph C Wu, Margaret A Goodell, Anne Brunet, Thomas A Rando

Faculty, Staff and Students Publications

Exercise has the ability to rejuvenate stem cells and improve tissue regeneration in aging animals. However, the cellular and molecular changes elicited by exercise have not been systematically studied across a broad range of cell types in stem cell compartments. We subjected young and old mice to aerobic exercise and generated a single-cell transcriptomic atlas of muscle, neural, and hematopoietic stem cells with their niche cells and progeny, complemented by whole transcriptome analysis of single myofibers. We found that exercise ameliorated the upregulation of a number of inflammatory pathways associated with old age and restored aspects of intercellular communication mediated …

Interspecies Interactions Within The Host: The Social Network Of Group B Streptococcus, Marlyd E Mejia, Clare M Robertson, Kathryn A Patras

Faculty, Staff and Students Publications

Group B Streptococcus (GBS) is a pervasive neonatal pathogen accounting for a combined half a million deaths and stillbirths annually. The most common source of fetal or neonatal GBS exposure is the maternal microbiota. GBS asymptomatically colonizes the gastrointestinal and vaginal mucosa of 1 in 5 individuals globally, although its precise role in these niches is not well understood. To prevent vertical transmission, broad-spectrum antibiotics are administered to GBS-positive mothers during labor in many countries. Although antibiotics have significantly reduced GBS early-onset neonatal disease, there are several unintended consequences, including an altered neonatal microbiota and increased risk for other microbial …

Acute High-Fat Diet Impairs Macrophage-Supported Intestinal Damage Resolution, Andrea A Hill, Myunghoo Kim, Daniel F Zegarra-Ruiz, Lin-Chun Chang, Kendra Norwood, Adrien Assié, Wan-Jung H Wu, Michael C Renfroe, Hyo Wong Song, Angela M Major, Buck S Samuel, Joseph M Hyser, Randy S Longman, Gretchen E Diehl

Faculty, Staff and Students Publications

Chronic exposure to high-fat diets (HFD) worsens intestinal disease pathology, but acute effects of HFD in tissue damage remain unclear. Here, we used short-term HFD feeding in a model of intestinal injury and found sustained damage with increased cecal dead neutrophil accumulation, along with dietary lipid accumulation. Neutrophil depletion rescued enhanced pathology. Macrophages from HFD-treated mice showed reduced capacity to engulf dead neutrophils. Macrophage clearance of dead neutrophils activates critical barrier repair and antiinflammatory pathways, including IL-10, which was lost after acute HFD feeding and intestinal injury. IL-10 overexpression restored intestinal repair after HFD feeding and intestinal injury. Macrophage exposure …